Inorganic electrolytes have been used to thicken polytetrafluoroethylene aqueous dispersions, as evidenced by Ribbans U.S. Pat. No. 3,830,770. Thickening of aqueous dispersions, i.e., increasing the viscosity of the dispersions, is ordinarily carried out to aid in maintaining stability of the dispersions, especially during storage. In particular, thickening of the dispersions aids in retarding the settling out of various ingredients, such as inert filler materials.
Addition of an inorganic electrolyte to such a dispersion results in an increase in the viscosity of the dispersion and thus causes it to thicken. Heretofore, once a dispersion had been thickened, viscosity could only be lowered by adding water. Addition of water dilutes the dispersion and results in a change in the concentration of the ingredients. Since many applications involve the use of uniform batches of dispersion, it would be desirable to be able to lower the viscosity of a dispersion without changing the volume (i.e., concentration).